1. Field of the Invention
The present invention provides for novel applications of chimeric coiled-coil molecule such as COMP-Ang1 for producing therapeutic angiogenesis, enhancing wound healing, recovering artherosclerotic erectile dysfunction, preventing vascular leakages including in sepsis and diabetic retinopathy. The invention also provides for applications of the chimeric coiled-coil molecule such as COMP-Ang1 for any blood vessel related disease such as shock, adrenal cortical insufficiency, hypertension, arthritis, stroke, ischemic brain diseases, asthma, and so on.
2. Description of the Background
Angiopoietin family proteins include four different angiopoietins, namely, angiopoietin-1 (Ang1), angiopoietin-2 (Ang2), angiopoietin-3 (Ang3) and angiopoietin-4 (Ang4) (Yancopoulos et al., 2000, Nature 407:242-248; Koh et al., 2002, Exp Mol Med. 34:1-11) (FIG. 1). Ang1 and Ang4 act as agonist to vascular endothelial cell specific receptor tyrosine kinase, Tie2, while Ang2 and Ang3 have been known to act as antagonist to Tie2 (Yancopoulos et al., 2000, Nature 407:242-248; Koh et al., 2002, Exp Mol Med. 34:1-11) (FIG. 1). However, recent reports indicated that Ang2 and Ang3 also can act as agonist in context dependent manner (Kim et al., Oncogene. 2000 14:4549-4552; Lee et al., FASEB J. 18:1200-1208) (FIG. 1). Very recent report indicated that all angiopoietins also bind and activate another vascular endothelial cell specific receptor tyrosine kinase, Tie1 (Saharinen et al., 2005, J Cell Biol. 169:239-243) (FIG. 1). Activation of Tie2 and Tie1 are involved in vasculogenesis, angiogenesis, lymphangiogenesis, and maintenance of endothelium integrity (FIG. 1).
Many reports (Suri et al., 1998, Science. 282:468-471; Thurston et al., 1999, Science. 286:2511-2514; Shyu et al., 1998, Circulation. 98:2081-2087; Chae et al., 2000, Arterioscler Thromb Vasc Biol. 20:2573-2578; Zhou et al., 2004, J Am Coll Cardiol. 44:897-903), indicate that Ang1 can be used for therapeutic angiogenesis in case of ischemic heart, limb, and brain because application of Ang1 produces healthy, non-leaky and stable blood vessel formation while currently used VEGF produces non-healthy, leaky and unstable blood vessel formation.
Biochemical organization of Ang1 is complicated. Schematic diagram of the protein structure of Ang1 indicates that amino acids 1-19 are the secretory signal sequences (S), amino acids 20-155 are the superclustering domain (SCD), amino acids 156-255 are the coiled-coil oligomeric domain (CCOD), amino acids 256-283 are the linker (L), and amino acids 284-498 are the fibrinogen-like domain (FLD) (FIG. 2). There are cysteines (C) at amino acids 41, 54, 265, 286, 315, 435, 437, 439, and 452 (FIG. 2). Once Ang1 is generated as recombinant protein, it is frequently insoluble, easily aggregated, stick and unstable in activity. For in vivo use of Ang1, a soluble, stable, and potent Ang1 variant, COMP-Ang1 was developed (Cho et al., PNAS 101:5547-5552, 2004; Cho et al., PNAS 101:5553-5558, 2004; U.S. patent application Ser. No. 10/273,180 and PCT/IB03/03814, which references are incorporated by reference herein in their entirety). COMP-Ang1 is more potent than native Ang1 in phosphorylating the Tie2 receptor in lung endothelial cells in vitro and in vivo (Cho et al., PNAS 101:5547-5552, 2004; Cho et al., PNAS 101:5553-5558, 2004; U.S. patent application Ser. No. 10/273,180 and PCT/IB03/03814).